ABSTRACT
In nature, free-living or planktonic populations of microorganisms are unusual; rather, they grow in an association with surfaces to form functional consortia known as biofilms. Microorganisms will often flocculate and form aggregates in nutrient-rich liquid environments such as waste treatment plants. Established biofilms may serve as reservoirs of microorganisms, facilitating the dispersal of cells into the bulk phase. This is a necessary aspect of the sessile mode of growth without which the organisms would be incapable of colonizing new sites. Biofilms are collections of microorganisms associated with a surface and organized within an extracellular polymer matrix. The resistance of bacterial biofilms and attached cells towards treatments with biocides and antibiotics are of particular interest in the context of microbiological challenge testing and screening for novel antimicrobial activity. Division of the attached cells within the glycocalyx results in the formation of microcolonies, which may coalesce to form a more extensive biofilm.
